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R&D project

Radiographic Simulation for assessing the Measurement Uncertainty of measurements of geometrical features using X-ray Computed Tomography (CTSimU)

Project period

Start: April 2018
End:   July 2021

Project description

The industrial X-ray computed tomography (CT) is the only measurement technology in coordinate metrology being able to measure a workpiece holistically with a single measurement. This approach enables the measurement of inner as well as outer geometry features, which is often not possible for other measurement technologies. However, the simulation of the CT measurement process offers basically the possibility to assess numerically the task-specific measurement uncertainty with admissible effort, while at the moment any experimental approach to determine the measurement uncertainty requires a large effort. Besides that, CT simulation will facilitate the optimization of the measurement, by e.g. the optimization of the CT scanning parameters. In spite of that, as a major drawback the reliability of simulation software currently could not be quantified for these applications. In this context, the Project CTSimU will perform a basis-qualification of radiographic simulation software for the simulation of CT measurements. This methodology should help to create trust for the user of the simulation software by its normative nature as well as it should enable, in the long-term, the determination of the CT measurement uncertainty using simulation. The basis-qualification is, in this context, understood as the verification of the basic capabilities, functionalities as well as correctness regarding physical phenomena of simulation software for the use of CT for dimensional measurements of industrial workpieces. Due to the high complexity of the CT measurement workflow, the radiographic simulation software for simulation of dimensional CT measurements available in the project CTSimU are tested and evaluated. The evaluation is based on assessing the measurement error of predefined samples of measurement task. If the tested radiographic simulation software successfully passes all tests, it can be considered basis-qualified. For the basis-qualification, an analysis of requirements is carried out, therefrom specification sheets as well as a test framework, with respective reference datasets, are created. The new test framework as well as the reference datasets and the test requirements sheets can be used to perform the basis-qualification of further radiographic simulation softwares. The main outcome of the Project CTSimU will be a draft for the German guideline VDI/VDE 2630 Part 2.2 “Basis-qualification of software systems for the simulation of dimensional measurements with X-ray computed tomography”. Simultaneously, this German guideline draft can serve as a pre-draft for a future international ISO norm.
A special focus of the PTB work in the Project CTSimU is the development of 2D- and 3D-based test scenarios as well as the metrological simulation and evaluation of the measurement results.

Project homepage: https://www.ctsimu.forschung.fau.de/

Project funding

The Project CTSimU is funded by the German federal ministry for economics and energy within the scope of the funding programme WIPANO with the grant agreement number 03TNH026D.

Project partner



Fabrício Borges de Oliveira, Markus Bartscher